textproduct: Rapid City

KEY MESSAGES

- Light snow to continue over the western South Dakota plains and the northern Hills through Friday. Additional accumulations of 2-5 inches in the hills and up to 3 inches on the plains.

- Another round of light precipitation moves through the area Saturday, with snow changing over to rain as warm air moves into the region.

- Above average temperatures begin Sunday and continue through the upcoming week.

DISCUSSION

(This Evening Through Thursday) Issued at 131 PM MST Thu Jan 29 2026

Upper level analysis has a ridge over the western CONUS with a deep trough over the Ohio and Mississippi River Valley resulting in northwest flow across the forecast area. Water vapor shows a shortwave pushing through the CWA, with additional energy moving toward the area in eastern Montana, and other waves embedded in the flow over southern Alberta and southern Saskatchewan. At the surface, a nearly stationary boundary extends across western South Dakota and the Black Hills. Latest radar has light snow continuing over the northern Black Hills and across most of the South Dakota plains, with snow ending over far northwestern South Dakota, and along the eastern fringes of the forecast area. Temperatures range from the upper 20s to middle 30s, thus snow is melting in some areas, which has limited accumulations.

Stalled out frontal boundary and baroclinic zone look to remain across the area through Friday. Embedded waves will support a prolonged period of light snow over western South Dakota plains. Froude numbers around 1 tail off early Friday morning, thus additional accumulations tonight and Friday in the northern Black Hills should be between 2 to 5 inches. Thus, the current Winter Weather Advisory already in place seems to be sufficient.

Surface high pressure builds over the eastern Dakotas Friday, nudging the stationary front to the southwest. Weak upper ridging pushes warmer air into region, as a Pacific front moves through the forecast area Saturday afternoon. This front will push the cold arctic air out of the region, replacing it with milder conditions. As the front crosses the area, precipitation looks to start out as snow before quickly changing over to rain. Forecast soundings indicate that a brief period of freezing rain is possible across northwestern South Dakota Saturday afternoon, but at this time ice accumulations look to be minimal.

The western upper ridge moves into the area by Sunday, but models are now pushing a weak upper trough through the area late Monday and Tuesday. A few showers will be possible along with breezy northwesterly winds. Temperatures look to remain mild as 850mb temps are still between 0C and 5C. By Thursday, the upper ridge strengthens again over the western CONUS, resulting in mainly dry and mild conditions.

AVIATION

(For the 18Z TAFS Through 18Z Friday) Issued At 1044 AM MST Thu Jan 29 2026

Low cigs and snow have reduced flight categories in the vicinity of the Black Hills with MVFR conditions reported at most locations and VFR cigs and vis in the northern foothills.

Expect only about a 20% chance of snow through the remainder of the TAF period at GCC, so have left off TAFs due to low confidence. On the other hand, occasional snow is likely to continue through the period at RAP. About a 20% chance that some rain will mix in Generally expect conditions to deteriorate through the afternoon and evening with LFR conditions currently forecast by 14Z Friday morning.

Expect northwesterly winds to become easterly overnight.

UNR WATCHES/WARNINGS/ADVISORIES

SD...Winter Weather Advisory until 5 PM MST Friday for SDZ024. WY...Winter Weather Advisory until 5 PM MST Friday for WYZ057.